Magnetic sound recording device



Nov. 25, 1941.

A. s'rAPELFELD-r 2,264,008

MAGNETIC SOUND RECORDING DEVICE Filed June 7, i959 Patented Nov. 25, 1941 MAGNETIC SOUND RECORDING DEVICE Arnold Stapelfeldt, Berlin, Germany, assignor to C. Lorenz Aktiengesellschaft, Berlin-Tempelhoi', Germany, a company Application June 7, 1939, Serial No. 277,780

Germany June 14, 1938 Claims.

Magnetic recording devices of the type designated as steeltone machines are known which comprise a machine wherein recordings are made magnetically on a steel tape or wire and include a mechanism coupled with 'the motor drive Vand having a hand or pointer for indicating the length of that part of the wireor tapeshaped record carrier which at the time is available for recording. Also switching means have been provided which act to stop the machine alter a predetermined part of the'record carrier has been uncoiled. In most of the latter cases indicating devices of the type having rotary pointers are employed. Furthermore, scales have been used which have a nut screw in engagement with a spindle yor lead screw and arranged to move along this spindle under the inuence of a guide rod for such nut. This rod is mounted on a casing in which the well-known bobbins or reels are contained, and is displaceable in its longitudinal direction. When now the nut comes against an adjusting ring the guide rod is disy placed and thereby acts to stop the machine.

'Ihis arrangement has the disadvantage that the machine will be stopped by every impact iniiuencing it and will be stopped also whenever the guide rod is touched. v

In accordance with the invention it is proposed to render the spindle displaceable along its axis and to eiect the stoppage of the machine by means of electric contacts controlled by the spindle. In this way any accidental stoppage of the machine will be obviated, as allof the movable members are mounted in the reel casing and as in addition these members are prevented by suitable holding means from being displaced under the inuence of shocks.

The invention will be understood from the lfollowing description, reference being had to the accompanying drawing in which spindle I is arranged. This spindle is mounted in supports T, iixed within ythe casing Q, and is revoluble and'axially displaceable in these supthe spindle I fromv a motor M, namely, the motor employed to drive the said reels. Spindle I is in .engagement with a nut'3 provided with an extension Z that projects into a longitudinal slot of a A scale S. In this way, whenever spindle I is rotating, nut 3will move along it. They guide extension Z also is the pointerfor sc ale S. The

lnut 3 carries a trunnion formed 'with an arm 4 and is on either side of this arm provided with a shoulder Yor stop b therefor, so that the arm 4 can be rotated through va certain angle and in a plane parallel to the spindle I. Scale S has a series of holes L spaced apart at distances b y which predetermined periods of operation of the machine aredened, such as one-minute periods, for instance. These holes are adapted to receive a pin 5 to be inserted in 'one orvanotherof the holesy in order to strike against arm 4 and thereby to stop the nut 3 in itsmovement along spindle I. The shoulders b are larranged to arrest arm 4 when ythe nut 3 is in the mid- Fig. l is a fragmentary'longitudinal sectional view illustrating one embodiment of the invention. Fig. la shows a fragmentary cross section of this embodiment along the section line A-A. Fig. 1b is a fragmentary top plan view of the structure shown in Fig. 1. Fig. 2 is a longitudinal sectional view representing a modiiication of the arrangement shown in Fig. l. Fig. 3 is a fragmentary sectional view illustrating a modiilcation of a detail of the construction represented in Fig. 2. Fig. 4 is a view similar to Fig. 3 and shows a second modification of such detail.

Q denotes a casing in which the well-known reels, not represented in the drawing, are located. Within this easing also a lead screw or position with respect to the pin 5, no matter in which direction the nut is travelling. As soon as nut 3 is stopped in this way the spindle i I owing to its continued rotation will be axially displaced in the direction opposite to the direction in which the nut 3 has travelled. Slide 2, being secured to spindle I, shares in any axial movement the spindle is subjected to. The slide 2 carries a stud 6 in engagement with a lever 1. Two sets of contact springs F tend to hold-'the lever l. in the mid-position represented in Fig. 1 and thus also tend to hold the slide 2 and spindle I in the mid-position. Whenever' now the nut 3,v`travelling along spindle I in one direction or the other, is stopped by the pin 5 inserted in one of the holes L, spindle I islongitudinallydisi milled at its lower end to present bevel surfaces Il, as shown. 'Ihe advantage of this construction is especially that the duration of recording and hence the length of that part of the wireor tape-shaped record carrier which is to be recoiled is adjustable at will and also, that the component parts of the ,machine need not be snugly fitted together.

As shown in Fig. 2, instead of the holes L. Fig. 1, a slot C may be provided in the casing Q. In this case screws or springs may serve to fix the pin I in the desired position in slot C. For instance, Vthe pin l shown in Fig. 2 has a clasp nut D screwed upon it, and is provided inside with a stop A. Nut D is serrated or may be a thumb screw. In the construction represented in Fig. 3 the pin 5 is clamped fast by a leaf spring BF arranged between the stop A of this pin and the upper wall of the casing Q.

Fig. 4 shows a spiral spring SF provided in lieu of this spring BF as shownl in Figure 3.

What is claimed is:

1. In a sound recording device, a frame, a drive means, a rectilinear scale, a spindle rotatable under control .of said drive means and displaceable along its axis, a pointer'cooperating with frame.

said scale to give an indication, adjustable stop means, means carrying said pointer and engaging said spindle and movable along said spindle under control of rotation thereof into contact with said stop means, and switch means for stopping said motor, said switch means being operated as said carried means contacts said stop means.

2. A device according to claim 1, in which the said ,spindle is a lead screw and in which the said adjustable stop means comprises a stop pin, said scale being provided with a series of holes adapted to receive such stop pin, and vin which said means carried by said spindle comprises a nut in engagement with 'such lead screw and adapted to come against said stop pin.

3. A device according to claim 1, in which the said spindle is a lead screw and in which the said adjustable stop means 'comprises a stop pin, said scale being provided with a series of holes adapted to receive such stop pin, said means carried by said spindle comprising a nut in engagement with such lead screw and adapted to come against said stop pin, this nut carrying a lever for the stop pins to strike against, and stops for such lever formed on said nut to arrest the said nut in its mid-position with respect to the stop pin.

4. A device according to claim 1, further comprising a slide fastened to the said spindle, and an electric contact device operated by said slide for stopping said drive means.

5. A device according to claim 1, further comprising a slide rigidly secured to the said spindle, an electric contact device for stopping said drive means, and a lever for actuating such contact device, this lever being engagedby said slide.

6. A device according to claim 1, in which said adjustable stop means includes a stop pin ad- Justably securable in a longitudinal slot in said '1. A device according to claim 1, in which said adjustable stop means includes a stop pin adjustably securable in a longitudinal slot in said frame, and means, comprisingY a clasp nut, for fixing this pin in such slot.

8. A device according to claim 1, in which said adjustable stop'means includes a stop'pin adjustably securable in a longitudinal slot in said frame, and means, comprising-a claspl nut at one end of the pin and spring means at the other end thereof, for fixing this pin in said slot.,

91 A device according to claim l, in which said adjustable stop means includes a 'stop pin adjustably securable in a longitudinal slot in said frame, and means, comprising a clasp nut at one d end of the pin and a leafy spring atthe other end thereof, for fixing this pin in said slot.

10. A device according to claim l, in which said adjustable stop means includes a-stopvl'pin adjustably securable in a longitudinal slot in said frame, and means, comprising a clasp nut at one end of the pin and a helical spring atv theiother end thereof,-for fixing this pin in said slot.

`ARNOLD rsiniestra;m'. 

